Different examples of analysis techniques based on the phase of voltage signals coming from measurements taken on an electrical network, in particular for network monitoring purposes, are shown in US patent application Nos. 2004/0032265 (Turner); 2002/0149375 (Hu et al.); 2002/0121903 (Hu et al.); and U.S. Pat. Nos. 6,694,270 (Hart); 6,690,175 (Pinzon et al.); 6,584,417 (Hu et al.); 6,721,671 (Roberts); 6,601,001 (Moore); 5,966,675 (Koeck); 5,839,093 (Novosel et al.); 5,764,044 (Calero); 5,724,247 (Dalstein); 5,659,242 (Calero); 5,506,789 (Russell et al.); 4,871,971 (Jeerings et al.); and 4,800,509 (Nimmersjo).
Examples of techniques proposed to locate faults on an electrical network are shown in U.S. Pat. Nos. 6,420,876 (Saha et al.); 6,256,592 (Roberts et al.); 5,485,093 (Russell et al.); 6,525,543 (Roberts et al.); 6,477,475 (Takaoka et al.); 6,597,180 (Takaoka et al.); 6,591,203 (Das et al.); and 6,476,613 (Saha et al.).
Despite all these techniques, there is still that the location of faults on electrical networks and more particularly distribution ones, is limited by many unknown parameters like the fault impedance, the complexity of the network, the load imbalance and the difficulty to build an appropriate network model. All this and other troublesome factors or elements harden the application of these techniques which, moreover, may prove to be unreliable or inaccurate.
These in-service fault location techniques indicate the distance of the fault, leaving way to an important number of possible positions for location of the fault on the electrical network.